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EP-4738363-A1 - OPTICAL STORAGE MEDIUM, SUPER-RESOLUTION INFORMATION READING METHOD AND DEVICE BASED ON MEDIUM, AND SUPER-RESOLUTION INFORMATION WRITING METHOD AND DEVICE BASED ON MEDIUM

EP4738363A1EP 4738363 A1EP4738363 A1EP 4738363A1EP-4738363-A1

Abstract

Optical Storage Medium and Super-Resolution Information Read-Write Method and Apparatus Based on the Same. The optical storage medium comprises the following components in molar percentages: a photoinitiator from 0.1% to 5%; an aggregation-induced emission dye from 0.1% to 5%; a metal ion compound from 0.1% to 5%; and a monomer from 85% to 99.7%. The information writing method includes: irradiating the optical storage medium with a solid beam of wavelength λ 1 to enhance the fluorescence intensity in the irradiated region; irradiating the surrounding area of the solid-beam-irradiated region with a hollow beam of wavelength λ 2 to suppress the fluorescence intensity in that surrounding area; and recording information by utilizing the fluorescence contrast between the irradiated region and the surrounding area, thereby forming information recording points with dimensions smaller than the diffraction limit. The present invention employs super-resolution writing and super-resolution reading based on stimulated emission depletion microscopy. It addresses issues inherent in conventional read-write methods, such as the inability to break the diffraction limit, low material transmittance, and limitations on the number of three-dimensional recording layers. This significantly enhances optical storage density and capacity.

Inventors

  • ZHAO, Miao
  • RUAN, Hao
  • WEN, JING
  • HU, Qiao

Assignees

  • Shanghai Institute of Optics and Finemechanics, Chinese Acamedy of Sciences

Dates

Publication Date
20260506
Application Date
20240403

Claims (13)

  1. An optical storage medium, comprising components: a photoinitiator, a monomer, a metal ion compound, and an aggregation-induced emission dye, wherein molar amounts of all the components in a material are shown as follows: the photoinitiator accounts for 0.1% to 5%, the aggregation-induced emission dye accounts for 0.1% to 5%, the metal ion compound accounts for 0.1% to 5%, and the monomer accounts for 85% to 99.7%.
  2. A super-resolution information write-in method based on the optical storage medium of claim 1, comprising: irradiating the optical storage medium by using a solid beam with a wavelength λ 1 , such that an aggregation-induced emission effect is generated in an irradiation area to enhance a fluorescence intensity; irradiating a surrounding area of the solid beam irradiation area by using a hollow beam with a wavelength λ 2 , such that an aggregation-induced emission suppression effect is generated in the surrounding area to suppress the fluorescence intensity; and recording information by using a fluorescence contrast between the irradiation area and the surrounding area to form an information recording point with a size smaller than a diffraction limit.
  3. The super-resolution information write-in method of claim 2, wherein central positions of the solid beam and the hollow beam coincide in three-dimensional space.
  4. The super-resolution information write-in method of any one of claims 2 to 3, wherein a fluorescence contrast between the information recording point and an information unrecording area is greater than 10:1.
  5. The super-resolution information write-in method of any one of claims 2 to 3, wherein the size of the information recording point is smaller than the diffraction limit λ 1 /2NA, wherein NA is a numerical aperture of an objective lens.
  6. The optical storage medium of claim 1, wherein the metal ion compound comprises one or more organic-solvent-soluble compounds containing Li + , Zn 2+ , Yb 3+ , Zr 4+ , or Mg 2+ .
  7. The optical storage medium of claim 6, wherein the aggregation-induced emission dye comprises one or more of tetraphenylethene, hexaphenylsiloxane, and stilbeneanthracene; the monomer comprises one or more of 1,6-hexanediol diacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate, di(trimethylolpropane) tetraacrylate, tri(2-hydroxyethyl) isocyanurate triacrylate, and dipentaerythritol pentaacrylate; and the photoinitiator comprises one or more mixtures of IRGACURE-250, IRGACURE-907, IRGACURE-184, IRGACURE-369, IRGACURE-819, IRGACURE-1173, IRGACURE-784, IRGACURE-ITX, and IRGACURE-DETC.
  8. The optical storage medium of claim 1, wherein the optical storage medium is attached to a substrate and is UV pre-cured.
  9. The optical storage medium of claim 8, wherein the optical storage medium is prepared by adopting the following method: (1) placing the photoinitiator with the molar ratio of 0.1% to 5%, the aggregation-induced emission dye with the molar ratio of 0.1% to 5%, the metal ion compound with the molar ratio of 0.1% to 5% and the monomer with the molar ratio of 85% to 99.7% in an acetone solution, performing ultrasonic mixing, and then, removing all the acetone solutions by oven baking to obtain an optical storage medium material; (2) mixing the optical storage medium material in step (1) with an organic solvent such as tetrafluoropropanol or acetone in a certain proportion, and dropping the solution on the substrate rotating at a low speed (a rotating speed is 200 rpm to 600 rpm); then, increasing the rotating speed of the substrate to 800 rpm to 2000 rpm to make the solution radially flow outwards on the substrate until the solution is uniformly distributed on the substrate; and finally, increasing the rotating speed of the substrate to 4800 rpm to 6500 rpm to completely evaporate and remove the mixed organic solvent; and (3) exposing the optical storage medium material uniformly distributed on the substrate and achieving first pre-curing by adopting a UV curing lamp to obtain a solid storage medium film.
  10. A super-resolution information readout method based on an optical storage medium, wherein the method comprises the following steps: irradiating the optical storage medium by using a solid beam with a wavelength λ 3 and a hollow beam with a wavelength λ 4 , wherein the optical storage medium is doped with an aggregation-induced emission dye; performing spontaneous radiation from ground-state electrons to excited-state electrons by using the solid beam with the wavelength λ 3 and stimulated radiation on the excited-state electrons by using the hollow beam with the wavelength λ 4 ; and collecting an aggregation-induced fluorescence enhancement signal to read out an information recording point; wherein the wavelength λ 4 is greater than the wavelength λ 3 .
  11. A super-resolution information write-in device based on an optical storage medium, comprising an optical path module and a control module; wherein the optical path module is configured to form a solid beam with a wavelength λ 1 and a hollow beam with a wavelength λ 2 and irradiate the optical storage medium by using the solid beam with the wavelength λ 1 , such that an aggregation-induced emission effect is generated in an irradiation area to enhance a fluorescence intensity, wherein the optical storage medium is doped with an aggregation-induced emission dye; irradiate a surrounding area of the solid beam irradiation area by using the hollow beam with the wavelength λ 2 , such that an aggregation-induced emission suppression effect is generated in the surrounding area to suppress the fluorescence intensity; and record information by using a fluorescence contrast between the irradiation area and the surrounding area to form an information recording point with a size smaller than a diffraction limit; and the control module is configured to control the z-direction displacement of an objective lens or the optical storage medium and regulate focal positions of the solid beam and the hollow beam in the optical storage medium.
  12. The information write-in device of claim 11, wherein the optical path module comprises a first write-in laser module, a first lens, a first aperture, a second lens, a first dichroic mirror, a second write-in laser module, a third lens, a second aperture, a fourth lens, a vortex phase plate, a second dichroic mirror, and the objective lens; wherein the first write-in laser module emits a beam of continuous light with a wavelength ranging from 200 nm to 400 nm or a pulsed laser with a wavelength ranging from 400 nm to 800 nm, which enters the objective lens through the first lens, the first aperture, the second lens and the first dichroic mirror and is focused to form the solid beam with the wavelength λ 1 to be stored into the optical storage medium; and the second write-in laser module emits a beam of continuous light or pulsed laser with a wavelength ranging from 500 nm to 800 nm, which forms the hollow beam with the wavelength λ 2 through the third lens, the second aperture, the fourth lens and the vortex phase plate, and then, the hollow beam enters the objective lens through the second dichroic mirror and the first dichroic mirror and is focused together with the solid beam with the wavelength λ 1 to the same position on the optical storage medium, wherein central positions of the solid beam and the hollow beam coincide in three-dimensional space.
  13. A super-resolution information readout device based on an optical storage medium, comprising a readout optical path module configured to form double beams that are a solid beam with a wavelength λ 3 and a hollow beam with a wavelength λ 4 , wherein the optical storage medium is doped with an aggregation-induced emission dye, and the double beams are used for irradiating the optical storage medium; perform spontaneous radiation from ground-state electrons to excited-state electrons by using the solid beam with the wavelength λ 3 and stimulated radiation on the excited-state electrons by using the hollow beam with the wavelength λ 4 ; and collect an aggregation-induced fluorescence enhancement signal to read out an information recording point; wherein the wavelength λ 4 is greater than the wavelength λ 3 .

Description

TECHNICAL FIELD The present invention relates to the technical field of optical storage, and in particular, to an optical storage medium, a super-resolution information read-write method, and an apparatus based on the same. BACKGROUND ART With the emergence of the Fourth Industrial Revolution centered on intelligent manufacturing and the rapid development of the internet, the Internet of Things, cloud computing, and artificial intelligence, data volume has experienced explosive growth. Currently, information storage methods dominated by magnetic storage technology generally suffer from disadvantages such as short lifespan and high energy consumption. In particular, with the surge in total data volume, the resulting storage media and power consumption losses will inevitably significantly increase the cost of data storage. In contrast, optical storage possesses the characteristic of long-term "offline" capability, with a lifecycle of up to 50 years. During this period, its power consumption is less than 1% of that of hard disk systems, enabling secure, long-term, energy-efficient data preservation while offering features such as resistance to electromagnetic interference and immutability. However, traditional optical storage systems are constrained by the optical diffraction limit, with recorded spot sizes approximately half the wavelength. During the information writing process, when the distance between adjacent recording spots is smaller than the scale of optical diffraction, the writing of the second spot interferes with that of the first, causing the writing areas of the two adjacent spots to overlap. Moreover, the contrast between written and unwritten regions is very low, making the two spots indistinguishable (Applied Physics Letters, 2008, 92(9): 90-93 and Optics Express, 2013, 21(9): 10831-10840). During the information reading process, constrained by the optical diffraction limit, super-resolution recording spots cannot be distinguished, thereby preventing the realization of super-resolution reading. Therefore, the limitation imposed by the optical diffraction limit presents significant challenges for optical storage, both in writing and reading information at super-resolution scales, hindering further increases in total storage capacity and limiting its application in the era of big data. Furthermore, super-resolution optical storage technologies based on green fluorescent protein and diarylethene dyes employ the simultaneous action of three laser beams to achieve super-resolution information writing, including two writing beams and one quenching beam. This approach achieves super-resolution recording through a quenching mechanism. However, both the writing and reading processes require pre-treatment of the medium material to maintain the stability of the recorded information's quenched state. Additionally, the storage system necessitates maintaining high three-dimensional coincidence for all three beams simultaneously, resulting in excessive system complexity. Moreover, the super-resolution effect based on the quenching principle is not particularly outstanding. Notably, using green fluorescent protein as the storage medium also has the drawback of a short storage lifespan (refer to CN108877844B and Nature, 2011, 478(7368): 204-208). In optical storage systems, in addition to breaking the diffraction limit to shrink the recording spot size to the super-resolution scale, the architecture can be extended from traditional and commonly used single-layer optical storage to a three-dimensional multi-layer storage framework. This approach enables full utilization of the originally unused 99.99% of the storage medium volume. Existing traditional optical storage systems based on reflective readout support up to six recording layers, offering limited improvement in storage capacity (see Wikipedia Contributors. Blu-ray[EB/OL]. (2019-02). https://en.wikipedia.org/wiki/Blu-ray).On the other hand, fluorescence-based three-dimensional optical storage leverages the high specificity and accuracy of fluorescent signal readout to effectively enhance the volume utilization of the storage medium. However, it is constrained by the transmittance of the medium material and the issue of inter-layer crosstalk during multi-layer writing (see Light: Science & Applications, 2014, 3(e177): 1-11), which prevents achieving a higher number of storage layers and thus limits the overall storage capacity improvement. Furthermore, fluorescence-based three-dimensional optical storage using polymers combined with fluorescent dyes (e.g., The Journal of Chemical Physics, 1957, 27(3): 758-763; Small, 2008, 4(1): 134-142; and Journal of Physical Chemistry A, 2009, 113(49): 13633-13644) predominantly employs conventional fluorescent dyes, which suffer from aggregation-caused quenching issues. For example, dyes such as pyrene, rhodamine, and coumarin emit strong fluorescence in a dissolved state, but their fluorescence quenches as aggregati